docs: def review(self) -> None:
          """ Used to play the WAV files and compare with the transcription. """
  
          for prefix in self.determine_prefixes():
              print("Utterance: {}".format(prefix))
              wav_fn = self.feat_dir / "{}.wav".format(prefix)
              label_fn = self.label_dir / "{}.{}".format(prefix,self.label_type)
              with label_fn.open() as f:
                  transcript = f.read().strip()
              print("Transcription: {}".format(transcript))
              subprocess.run(["play", str(wav_fn)])